In recent years, many video movies, for example, have been broadcast on pay television. When main programs such as video movies are broadcast on pay television, an additional information program such as a CM (commercial) video program, a promotion video program, or the like is broadcast between main programs, i.e., before the start of a video movie or after the end of a video movie, but not inserted in the middle of a video movie.
Present pay television programs are broadcast through a single channel, and CM video program, promotion video programs, or the like (hereinafter referred to as "CM video programs") are broadcast together before the start of a video movie or after the end of a video movie. Since video movie materials and CM video program materials are different from each other, it is easy to update CM video program materials.
Recently, there have been demands for a video-on-demand (VOD) system service as one type of pay television which allows users to view a video program from its beginning at any time they want. Various studies on VOD systems show, however, that since a complete VOD system needs extremely many channels depending on the number of subscribing users, it is difficult to collect the investment made in the VOD system. For this reason, the VOD system is not among various types of pay television that are being studied.
One recent alternative to the VOD system is a service in which video programs of the same contents are sequentially broadcast at certain time intervals ranging from 5 to 15 minutes, for example, in a limited number of frequency channels, and the user selects one of the channels which is most convenient for them at the time of starting to use the service, so that the user can see the video program from the beginning at a desired time though he or she may have to wait a little while. This service is referred to as a near video-on-demand (NVOD) system.
The NVOD system has one problem to be solved yet as to how CM video programs are incorporated into video programs broadcast in the channels. The very nature of such CM video programs requires them to be updated at appropriate intervals so that they will provide latest commercial information.
According to one solution, as many sets of video movie materials and CM video materials as the number of the available channels are prepared, and independently broadcast at certain time intervals in the respective channels. If, however, a pay television broadcasting station is able to establish an NVOD system which broadcasts only one set of video movie materials and CM video materials at certain time intervals in a plurality of channels, then such an NVOD system will be highly convenient and inexpensive for users. It is desirable in such an NVOD system to be able to separate CM video materials from video movie materials for easily updating the CM video materials at appropriate times.
Therefore, it is an object of the present invention to provide an NVOD system capable of incorporating CM video programs, promotion video programs, or the like into video programs, and a broadcasting method for such an NVOD system.
Another object of the present invention is to provide an NVOD system which is capable of easily updating CM video programs, promotion video programs, or the like to be incorporated into video programs.